As known in the art, a “stackable switch” is a network switch that can operate independently as a standalone device or in concert with one or more other stackable switches in a “stack” or “stacking system.” FIG. 1A illustrates the front face of an exemplary stackable switch 100 according to an embodiment. As shown in FIG. 1A, stackable switch 100 includes a plurality of data ports 102 that are operable for connecting switch 100 to one or more hosts and/or data networks. Stackable switch 100 also includes a set of stacking ports 104 that are operable for linking switch 100 to other switch units in a stacking configuration. Stacking ports 104 can be dedicated ports (i.e., ports designed specifically for stacking) or high bandwidth data uplink ports that can operate in a stacking mode.
Some stackable switches support a feature known as “trunked stacking.” With this feature, multiple stacking ports can be grouped together to behave as a single logical port (referred to as a “stacking trunk”), thereby improving resiliency and bandwidth between units in a stacking system. By way of example, FIG. 1B depicts a stacking system where stackable switch 100 of FIG. 1A is connected to another stackable switch 110 via links 112 and 114. The stacking ports at the ends of these links (i.e., ports 116, 118 on switch 100 and ports 120, 122 on switch 110) are grouped into stacking trunks 124 and 126 respectively. In this example, when traffic needs to flow between switches 100 and 110, the traffic may pass over either link 112 or 114 since they are considered part of the same logical connection. This increases the aggregate bandwidth between switches 100 and 110 and provides redundancy in the case of a link failure.
Unfortunately, despite the advantages provided by trunked stacking, this feature can also significantly complicate stacking system administration and management. For instance, in order to configure stacking trunks 124 and 126 shown in FIG. 1B, a system administrator must typically enter trunk creation commands at each switch 100 and 110, which require knowledge of the unit IDs of the switches, the port numbers of the trunked ports, and the format/operation of the commands themselves. Although this manual configuration process may be workable in a small-scale stacking system, it can quickly become cumbersome, time-consuming, and error-prone in systems with larger and/or more complex topologies.
Further, the physical connections between units in a stacking system must correctly match the configuration entered via the trunk commands. If one or more of the physical connections are incorrect, the system administrator must generally inspect the cabling at each unit in order to find the incorrect connection(s), which again can be very difficult and time-consuming in a large/complex topology.